The Keyence FU-77G belongs to the FU Series of fiber optic units. It functions as a thrubeam type sensor, which means the emitter and receiver fibers face each other. This design detects objects when they interrupt the light beam between the two fiber heads. Because of its M4 threaded shape, technicians can mount the FU-77G quickly on machinery and production lines. The small optical axis diameter of ø1.13 mm allows for precise detection of tiny targets. Additionally, the stainless steel construction adds durability in demanding industrial settings. This unit works with compatible fiber amplifiers from Keyence to form a complete sensing system. Users often choose the FU-77G for tasks that require high accuracy in confined spaces.
The FU-77G provides key optical and mechanical parameters. First, the optical axis diameter measures ø1.13 mm. This small beam size supports the detection of miniature components and thin edges. Second, the fiber unit length is 1 m. The manufacturer does not allow cutting this fiber, so installers must plan cable routing carefully. Moreover, the threaded M4 head enables direct mounting into tapped holes or brackets. The minimum bend radius is R10 mm with stainless steel reinforcement. Therefore, excessive bending or tight loops can damage the fiber and degrade signal quality. In addition, the FU-77G detects a minimum object of ø0.005 mm under optimal gain and distance settings.
The FU-77G operates within a wide temperature range. Ambient temperature limits are -40 to +50 °C. This range suits cold storage rooms, outdoor enclosures, and standard factory floors. Furthermore, the stainless steel construction resists corrosion and mechanical wear. The fiber unit itself weighs approximately 39 g. Besides the fiber, the M4 threaded head provides a secure mechanical interface. Meanwhile, the R10 mm bend radius protects the optical core from stress fractures. These environmental ratings make the FU-77G suitable for long-term deployment in automation equipment.
Installation of the FU-77G requires attention to alignment and fiber routing. First, mount the M4 threaded head into a compatible bracket or tapped hole. Next, align the emitter and receiver fibers so they face each other directly. The optical axis should be perpendicular to the target surface for the strongest signal. Additionally, connect the fiber ends to a compatible Keyence fiber amplifier. During commissioning, adjust the amplifier gain to match the application. However, avoid bending the fiber below R10 mm at any point. Finally, secure the cable with clamps to prevent vibration damage.
1 × Keyence FU-77G Fiber Unit
Q1: What is the detection principle of the FU-77G?
A: The FU-77G is a thrubeam fiber unit. It detects objects when they block the light path between two fiber heads.
Q2: Can I cut the fiber cable to shorten it?
A: No. The FU-77G fiber unit has a fixed length of 1 m and cutting is not allowed.
Q3: What fiber amplifier works with this unit?
A: Use Keyence fiber amplifiers from the FS-V, FS-T, or FS-M series for best results.
Q4: What is the minimum detectable object size?
A: Under optimal settings, the FU-77G can detect objects as small as ø0.005 mm.
Q5: How do you ship this product?
A: We ship via Fedex, UPS, and DHL for global delivery.
| Brand Name | |
| Model No. | FU-77G |
| Product Type | Fiber Unit |
| hasMerchantReturnPolicy | Adjust according to reality |
| Shippingdetails | Adjust according to reality |
